A. Field of the Invention
The Invention is an apparatus for manually encoding symbols for input to a computer using the fingers of one hand. The Invention is also a method of encoding symbols using the apparatus.
B. Statement of the Related Art
As used herein, the term “computer” means any device that includes a microprocessor with access to computer memory and that can be configured to convert signals from the apparatus of the Invention to corresponding symbols. By way of example and without limitation, the term ‘computer’ includes a mainframe computer, a desktop computer, a laptop computer, a notebook computer, a netbook computer, a tablet computer, a distributed computing system, a smart phone, a personal digital assistant, an embedded system, and any other system having a microprocessor with access to computer memory.
The term ‘data input device’ means any apparatus that is capable of receiving an instruction manually from a human being and that is capable of communicating with the microprocessor. The term ‘symbol’ means all of the symbols or instructions that may be communicated by a keystroke on a conventional QWERTY computer keyboard or by a keystroke on any computer keyboard in any language, and capable of data entry.
The most widely utilized data input device is the familiar keyboard arranged according to the QWERTY layout. QWERTY and all derived keyboards are a holdover from the days of mechanical typewriters. QWERTY-type keyboards generally are configured for two-handed input, are operable from a seated position often while watching the typing fingers. Despite the continuing popularity of the QWERTY keyboard, creating an easy-to-use one-handed keyboard remains a constant goal of developers and innovators.
Prior art data input devices suitable for one-hand operation fall into a few general categories: chording keyboards, keyboards with clusters of small keys, and multi-axial switch keyboards.
A “chording” keyboard requires that the operator press two or more keys at a time to form a ‘chord’ encoding a single symbol. Chording keyboards allow one-handed touch-typing and have the advantage of simplicity of construction. Chording keyboards are difficult to learn and difficult to operate. Up to five keystrokes may be needed to encode a single symbol. The chording keyboard operator must undergo extensive training and must learn a complex set of relationships between characters and chords. Difficult combinations of finger presses make operation a challenge. Premature release or early operation of one of the keys in a combination, or an unwanted combination occurring during a transition, often results in unwanted entry. This problem worsens with increased speed of operation.
In contrast with the chording keyboard, a keyboard featuring a single-keystroke-per-symbol mode of operation is much simpler for the user to comprehend, learn and perform. There are problems in constructing a one-handed keyboard using single keystroke technology; namely, such a keyboard requires a large number of keys and those keys must fit in a small space. One way to fit many keys into a small space is to make the keys small. See, for example, U.S. Pat. No. 4,849,732 issued to Dolenc on Jun. 18, 1989, which teaches four clusters of small keys; each cluster of keys is within reach of a dedicated finger.
Still another proposal was to use multi-contact switches. Such an approach is disclosed in U.S. Pat. No. 2,532,228 to Hesh, issued Nov. 28, 1950. Another example is U.S. Pat. No. 4,584,443 to Yaeger issued Apr. 22, 1986, where each finger of both hands operates a dedicated key. Each key of Yaeger can encode several symbols by moving in different directions.
Keyboards with key clusters or with multifunctional keys have disadvantages. Manual discrimination and actuation by the operator of a single target key among many other small keys is difficult and requires hand motions that are un-ergonomic, deliberate, tense, and slow. Keyboard designed for one-handed operation typically use switches operated by a spring-loaded plunger. To operate such a switch requires a sequence of actions, for example, a vertical key-press, a stop, and a rise of a finger. Engaging in the sequence for each key press or switch actuation consumes the operator's time and effort.
Tablet computers and other hand-held devices such as smart phones substitute a virtual keyboard on a touch screen for a physical keyboard and mouse. Although this innovation makes the computer more portable, it is a costly compromise. A virtual keyboard on a touch screen can provide only basic functionality to the computer and is ill suited for input of large amounts of data.
In addition to the touch screens on tablets and smart phones, another computing apparatus slowly is coming into use; namely, a computer capable of projecting a detailed screen image to the eyes of the user from a head-mounted apparatus. Computers of this type are already in use in the military and by enthusiasts of mobile computing. Such computers have no screen that can be touched and the conventional two-handed keyboard is not suitable for the mobile applications for which such computers are best adapted.
The tactile sensation and feedback of a full size computer keyboard sets the standard against which all alternative keyboards are measured. The full-sized QWERTY keyboard allows for fast, powerful, “ballistic” punching strokes to the spring-loaded and often deeply yielding keys, providing excellent motion and tactile sensation. In contrast, smaller keyboards, such as used in calculators, employ micro switches that must be operated with slower, more deliberate strokes. The use of a small keyboard requires that the operator view the keys, and designers of such keyboards generally use keys having a spring-operated “snap-action” or “tipping-point” mechanism, to communicate contact closure to the user in the form of perceived “click.” An additional function of the snap-action mechanism is to reduce contact bouncing. The need for the snap mechanism is an indication of inadequacy of sensation induced by the vertical stroke to the key. While the snap-action mechanism significantly enhances feedback, it also increases the spring tension and the actuator travel distance, effectively delaying the contact closure and slowing keyboard operation. Nevertheless, switches of this type prevail in keyboards designed for use by one hand.
A one-handed data entry device with the functionality of a QWERTY keyboard and that is portable, non-intrusive and easy to use is needed. Such a device was taught by U.S. Pat. No. 7,038,659 to Rajkowski, issued May 2, 2006, which is incorporated by reference as if set forth in full herein. The prior art does not teach the improved data input device of the invention.